Pump assembly

ABSTRACT

A pump assembly includes an electric drive motor (4, 6), an impeller, driven by the drive motor (4, 6), and a valve device (18) situated in a flow path through the pump assembly, which is movable between a first and a second switching position. The valve device (18) is coupled to the drive motor via a first coupling such that a movement of the drive motor (4, 6) is transmitted onto the valve device (18) and the valve device is movable from the first into the second switching position by rotation movement of the drive motor. The first coupling is releasable by way of increasing the speed of the drive motor (4, 6) and/or increasing the pressure at the outlet side of the impeller and/or by way of slip, such that the coupling between the drive motor (4, 6) and the valve device (18) is reduced or lifted.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a United States National Phase Application of International Application PCT/EP2018/056086 filed Mar. 12, 2018, and claims the benefit of priority under 35 U.S.C. § 119 of European Application 17 160 834.2, filed Mar. 14, 2017, the entire contents of which are incorporated herein by reference.

TECHNICAL FIELD

The invention relates to a pump assembly, in particular to a centrifugal pump assembly with an electric drive motor and with at least one valve device which is situated in a flow path through the pump assembly and which is movable at least between a first and a second switching position.

TECHNICAL BACKGROUND

Pump assemblies which contain a valve device which permits the switching between two possible flow paths, through which the centrifugal pump assembly delivers, are known. Here, valve devices which switch in a manner depending on the rotation direction of the centrifugal pump assembly, which is to say lead to the flow into different flow paths in a manner dependent on the rotation direction are known. Such a pump assembly which comprises a switch-over device, with the help of which one can switch between two inlets of the pump assembly, in order to selectively suck fluid from one of the two inlets is known for example from DE 9013992 U1. The pump assembly which is disclosed there comprises a relatively complicated mechanism which comprises an onflow element which is situated at the delivery side and which is subjected to onflow by the outlet-side flow produced by the pump assembly and which can be moved into two different positions depending on the rotation direction and therefore the flow direction. A valve element at the suction side of the pump assembly is switched between the two inlets via a lever system which is connected to the onflow element.

SUMMARY

With regard to this state of the art, it is an object of the invention to improve a pump assembly with an integrated valve device to the extent that a simpler construction of the pump assembly is achieved with a simultaneously increased reliability of the switching function of the valve device.

With regard to the pump assembly according to the invention, it is the case of a centrifugal pump assembly. The pump assembly comprises an electrical drive motor which is preferably configured as a wet-running electrical drive motor, i.e. as a canned motor. The pump assembly according to the invention can be configured for example for use as a circulation pump in a heating facility and/or air-conditioning facility. In particular, the pump assembly is configured for delivering water.

The pump assembly comprises at least one impeller which is driven by the drive motor. A valve device is which is movable at least between a first and a second switching position is moreover integrated into the pump assembly. Here, the valve device is preferably configured such that it provides a valve function for the fluid flow which is delivered by the pump assembly.

According to the invention, the valve device is configured such that it is movable via the electrical drive motor of the pump assembly, i.e. via the drive motor which drives the impeller. For this, the valve device is coupled to the drive motor via a first coupling in a manner such that the valve device is movable from the first into the second switching position by way of a rotation movement of the drive motor. This means that the movement of the drive motor can be transmitted onto the valve device by the first coupling, so that the valve device is directly or indirectly moved by the drive motor. Inasmuch as the drive motor is configured such that it can be driven in two rotation directions, according to a preferred embodiment it would be possible to move the valve device also back again from the second into the first switching position via the respective rotation movement of the drive motor. According to the invention, the first coupling is moreover configured such that by way of increasing the speed of the drive motor and/or increasing the pressure at the outlet side of the impeller and/or slip, it is releasable in a manner such that the coupling effect between the drive motor and the valve device can be reduced or lifted. By way of this, it is possible to utilize the drive motor in certain operating conditions in a targeted manner, in order to move the valve device, whereas in other operating conditions, if e.g. the increased pressure or the increased speed is provided, to however not move the valve device. Usefully, the valve device is thereby configured such that the coupling is released in the normal operating condition of the pump assembly, i.e. when fluid is delivered by the impeller in normal operation, so that in this condition the valve element remains in an assumed switching position.

According to a special embodiment of the invention, a gear which changes or converts the movement direction and/or the movement speed between the drive motor and the valve device can be provided between the drive motor and the valve device. The gear can be configured for example as a reduction gear which reduces a speed of the valve device or of a valve element of the valve device, with respect to the speed of the drive motor. Alternatively or additionally, a rotation movement of the drive motor could be converted into a linear movement of the valve element by a gear such as a spindle drive.

The drive motor is preferably electrically controlled or regulated so that it can be driven at different speeds and/or in different rotation directions. A control device can be provided for this, said control device regulating or controlling the drive motor accordingly. In particular, the control device can be equipped with a frequency converter for the speed change of the drive motor. According to a further preferred embodiment of the invention, the control device is configured such that it not only activates (controls) the drive motor in a manner such that the drive motor runs at different speeds, but also in a manner such that different acceleration courses can be realized on accelerating and/or braking the drive motor.

The configuration according to the invention has the advantage that on the one hand one can make do without a separate drive motor for the valve device, but that on the their hand one can make do without complicated mechanisms for the transmission of a force which is produced by the flow, onto a valve element. In contrast, the force transmission can be effected by the first coupling. The efficiency of the pump assembly can moreover be improved since the valve device essentially does not compromise the normal operation.

According to a preferred embodiment of the invention, at least one stop can be provided, said stop holding the valve device in a defined switching position, for example in the first or second switching position. Further preferably, two stops can be provided, wherein each of the two stops defines a switching position of the valve device and the valve device is movable between the two switching positions. This movement is effected via the first coupling and by way of a suitable activation of the drive motor, in particular via the described control device.

The valve device preferably comprises no further electrically activated switching elements for switching and/or holding the valve device. In contrast, the valve device is moved between the switching positions solely by the drive motor.

According to a preferred embodiment of the invention, the pump assembly comprises at least one second releasable coupling between at least one movable part of the valve device and a valve casing which surrounds the impeller. This second releasable coupling is movable from a released first coupling position into a holding coupling position by way of the pressure at the outlet side of the impeller. Here, the at least one releasable coupling does not need to engage on the pump casing in direct manner, but in contrast can also engage on the pump casing in an indirectly holding manner, by way of the coupling engaging with a component which is connected to the pump casing. What is essential with the embodiment of the second releasable coupling is the fact that in its holding, second coupling position it prevents a movement of the valve device. Here, preferably in one operation condition of the pump assembly, the second releasable coupling comes into holding engagement, i.e. into its holding, second coupling position, in which the first coupling reaches its released position. One can therefore succeed in the valve device being moved into a desired switching position in one operating condition of the drive motor, in particular in an operating condition with a lower speed and/or lower acceleration, Subsequently, by way of a speed increase and/or a particularly high acceleration of the drive motor, one can succeed in the second releasable coupling coming into holding engagement, so that the valve device remains and is held in the reached switching position. Here, preferably the first coupling simultaneously disengages or has a slip which permits the second rotation of the drive motor with the impeller.

The first and the second coupling are preferably configured in a manner such that in its released position, the first coupling has a smaller holding force than the second coupling in its holding, second coupling position. Conversely, the first coupling in its coupled position preferably has a greater holding force that the second coupling in its released, first coupling position. This means that when it is engaged, the first coupling can transmit a greater force or a greater torque that the second coupling in its released, first coupling position. The valve element can therefore be moved between two switching positions in this switch condition. If the first coupling is located in its released position and the second coupling in its holding coupling position, then the second coupling can transmit a greater force or a greater toque than the first coupling, so that the valve device is held in its reached switching position and cannot be moved by the drive motor via the first coupling.

Further preferably, the drive motor is configured such that on operation of the pump assembly, it produces a torque which is larger than the holding force of the first coupling in its coupled position. By way of this, one prevents the first coupling from preventing the rotation of the drive motor and thus of the impeller in normal operation of the pump assembly.

The valve device can preferably be configured as a switch-over valve which permits a switching between two flow paths. Alternatively or additionally, the valve device can comprise a mixing device, in which fluid from two flow paths is mixed, wherein the mixing device is configured in a manner such that the mixing ratio is different in the two switching positions of the valve device. With the embodiment as a mixing device, the valve device preferably comprises more than two switching positions and can be movable in several steps or in a stepless manner, for example between two switching positions which define the end positions. The use as a switch-over valve can be used for example in a heating facility, in which a switch-over valve is required, in order to switch a heat transfer medium flow between a heat exchanger for heating service water and at least one heating circuit for heating a building. A mixing device can also be applied in a heating facility, for example to reduce the temperature of a heat transfer medium by way of admixing fluid from a return of the heating facility. This can be useful e.g. for the use in a floor heating, concerning which as a rule it is necessary to reduce the feed temperature provided by a heating boiler, by way of admixing the heat transfer medium from the return.

The valve device can preferably provide a valve function in a flow path at the suction side of the impeller and/or a valve function in a flow path at the delivery side of the impeller. The valve device can therefore be arranged in particular as a switch-over device at the suction side, so that the impeller sucks fluid from a first or a second suction-side flow path depending on the switching position of the valve device. Alternatively, a switch-over device could be arranged at the delivery side, so that the pump assembly delivers into a first or a second delivery-side flow path depending on the switching position of the valve device. If the valve device is configured as a mixing device, this can be arranged at the delivery side for example such that two flow paths in the mixing device run out at the delivery side into a mixing point and that the mixing ratio between two flows is changed depending on the switching position of the valve device. Here, preferably one of the two flow paths runs through a heat exchanger of a heating or cooling device, downstream of the pump assembly, in order to control the temperature of fluid delivered by the pump assembly, i.e. to heat or cool it. Fluid which is not temperature-regulated is preferably located in the other flow path, and this can then be mixed with the temperature-controlled fluid in the mixing device. Alternatively, a mixing device could also be arranged at the suction side of the pump assembly, so that the pump assembly sucks e.g. a fluid which is mixed from two flow paths.

According to a further preferred embodiment, the valve device comprises at least one movable valve element as well as stop elements which define the first and the second switching position and of which preferably at least one can be adjusted in its position. It is possible to regulate the end positions or the switching positions of the valve device by way of the ability to adjust one or more stop elements. The stop elements prevent the valve device or the valve element from being moved beyond the desired switching position. The stop element therefore leads to a positive engagement between the valve element and the stop element, so that a further movement of the valve element is prevented.

According to a further preferred embodiment of the invention, the valve device comprises at least one movable valve element which interacts with two valve openings in a manner such that in a first switching position of the valve device a first valve opening is covered by the valve element to a greater extent than in the second switching position and in the second switching position a second valve opening is covered by the valve element to a greater extent than in the first switching position. If the valve element is configured as a switch-over valve, then in the first switching position the second valve opening is opened and the first valve opening is closed. Conversely then, in the second switching position the second valve opening is closed and the first valve opening is opened. Intermediate positions or intermediate switching positions, in which both valve openings are simultaneously opened but to a different extent are preferably possible in the case of the configuration of the valve device as a mixing device. A mixing ratio can therefore be changed by way of changing the openings degrees of the two valve openings. Preferably, the at least one movable valve element is configured such that when a valve opening is opened by a certain amount, the other valve opening is simultaneously closed by the same amount.

Such a reciprocity of the closure of the two valve openings can be realized with a valve element or however also with two valve elements if these are mechanically coupled to one another.

According to a further preferred embodiment, the valve device comprises a movable valve element which comprises at least one sealing surface and a pressure surface, wherein the pressure surface is connected to a delivery chamber which surrounds the impeller, in a manner such that the valve element is pressed with the sealing surface against a contact surface (bearing surface) by way of the pressure acting upon the pressure surface, wherein the contact surface preferably forms a valve seat. With such an embodiment, the valve element together with the contact surface can assume the function of the second coupling which is described above. If the valve element is pressed against the contact surface by way of pressure in the delivery chamber, then preferably such a friction fit arises between the sealing surface and the contact surface that the valve element is fixed in the reached switching position. This friction fit could additionally be assisted by a positive fit given a suitable configuration of the sealing surface and the contact surface. A sealing is simultaneously achieved via the bearing contact of the sealing surface if the bearing contact is a valve seat. If the pressure in the delivery chamber is lower, then the sealing surface preferably disengages from the contact surface or preferably from a valve seat, so that an easy movability of the valve element with a reduced friction is ensured. The valve seats can preferably surround valve opening, as have been described beforehand. A sealing of the flow paths to the outside is then achieved by way of the bearing contact of the at least one sealing surface. Moreover, a sealing surface can also be pressed against a contact surface or a valve seat such that a sealing between the suction chamber and the delivery chamber of the pump assembly is achieved by the bearing contact. Several valve seats, on which one or more sealing surfaces of the valve element can come to bear given an adequately large pressure in the delivery chamber, can therefore be provided, in order to achieve the necessary sealings of the flow paths. A restoring element, for example a restoring spring can preferably be provided, and this restoring element disengages the valve element with the sealing surface from the contact surface when the pressure in the delivery chamber falls below a predefined valve, i.e. the force produced on the pressure surface by the pressure in the delivery chamber is smaller than the restoring force which is produced by the restoring element. An easily movability of the valve element is thus ensured given a low pressure.

The valve device can further preferably comprise a rotatable valve element. I.e. the valve element is moved between the switching positions by way of a rotating movement, wherein the rotation axis further preferably is aligned with the rotation axis of the impeller or of the drive motor, which permits a particularly simple coupling without further gear means. The rotatable valve element is preferably releasably coupled to a rotor of the drive motor via the first coupling, wherein the coupling does not need to engage on the actual magnet rotor but also on a component such as a shaft or the impeller, which is connected to the magnet rotor. The rotatable valve element is rotatingly co-moved via the rotor of the drive motor when the first coupling is engaged.

The drive motor is preferably driveable in two rotation directions and the valve device is configured in a manner such that its first switching position can be reached by way of the drive of the drive motor in a first rotation direction and its second switching position by way of the drive of the drive motor in a second rotation direction. A restoring means or a force generating means which rotates the valve element back into a predefined initial position or switching position on switching off the drive motor can also be provided instead of a movement of the valve element in two rotation directions by way of the drive motor. This for example can be a magnetic restoring means, restoring means acting by way of a spring force or one which acts by way of gravity.

The first and/or the second coupling can preferably be a frictional coupling, a magnetic coupling and/or a hydraulic coupling which further preferably have a slip. If the first coupling has slip, then after reaching a predefined switching position when the valve element of the valve device or the valve device is fixed in the switching position, this slip permits the drive motor to be able to rotate further without becoming blocked by the fixation of the valve device. A valve element for example can therefore hit a stop, whereupon the coupling then slips through, which is to say that the drive motor can rotate further due to the slip in the coupling. Particularly preferably, a hydraulic coupling can be realized via the fluid which is delivered by the impeller. The fluid can hence be brought into rotation in the rotation direction of the impeller by way of the impeller in the inside of the pump casing and can drive the valve element via the friction on a part of the valve device, in particular directly on this valve element. The hydraulic flow flows further when the valve element or the valve device reaches a switching position and is fixed there, wherein the remaining hydraulic friction losses only occur at the surfaces. I.e., the loss energy which is present in any case and which is converted into a movement of the valve device or of the valve element can therefore be used for moving the valve device.

Further preferably, the first coupling comprises at least one coupling element which is movable between a coupled and a released position, wherein the movement direction between the coupled and the released position preferably runs transversely to a force direction of the force which is to be transmitted by the coupling onto the valve device. In the coupled position, a non-positive and/or positive engagement exists between the coupling element and an opposite coupling surface. The coupling element is movable such that it can disengage from the coupling surface, so that the valve element can then no longer be moved or caught and remains in its assumed switching position. The movement direction between the coupled and released position preferably lies in a direction which is different from the force transmission direction, by which means it is ensured that the coupling element is not moved out of engagement by the force to be transmitted. Particularly preferably, the movement direction runs normally to the force direction or a plane, in which the force direction runs. The latter can be the case for example if the coupling serves for the transmission of a torque. The movement direction then preferably runs along the rotation axis and thus transversely and in particular normally to the plane, in which the force is transmitted.

Particularly preferably, a valve element of the valve device can simultaneously form the movable coupling element. The valve element can hence comprise a coupling surface which can engage with an opposite coupling surface which is preferably arranged on the rotor or impeller, in order to move the valve element, in particular in a rotating manner. Here, a non-positive and/or positive engagement can be envisaged. The coupling element can further usefully be subjected to a biasing force via a biasing element, said biasing force forcing the coupling element into the coupled position. This means that the first coupling is in coupling engagement in the idle position. This engagement is then preferably made to disengage by way of the pressure occurring in the delivery chamber or by way of a higher speed of the drive motor. If the drive motor is switched off, then this force releasing the coupling then drops again, so that the biasing force forces the coupling back into the coupled position.

Further preferably, the coupling element comprises a pressure surface, whose connection to a delivery chamber surrounding the impeller and whose arrangement being such that pressure acting upon the pressure surface produces a force which is directed oppositely to the biasing force. The coupling element is displaced if the pressure in the delivery chamber increases to such an extent that the pressing force produced by the pressure surface exceeds the biasing force, wherein the coupling element is arranged such that it is moved into its released position given this displacement, i.e. the first coupling disengages and the valve element is not moved further by the drive motor, but remains in its assumed switching position. If the pressure reduces, for example when the pump assembly is switched off, then the pressing force weakens and the biasing force again becomes the greater force, so that the coupling is again moved into the coupled position. The valve element or the valve device can then be moved again into another switching position with the next start-up of the drive motor.

According to a further preferred embodiment of the invention, the coupling element can comprise a coupling surface which in the coupled position is in frictional contact with a counter coupling surface, wherein the coupling surface and the counter coupling surface are configured and surrounded by a lubricant such that a lubricant film which overcome or lifts the frictional contact forms between the coupling surface and the counter coupling surface on increasing the speed of the drive motor. The fluid which is delivered by the pump assembly, for example water is preferably applied as a lubricant. The coupling then functions in the manner of a plain bearing. Given an adequately high speed, a lubricant film forms between the coupling surface and the counter coupling surface, so that the frictional contact between the surfaces is lifted and these can slide on one another in the manner of a plain bearing. A coupling which can be disengaged by way of a speed increase can therefore be created. I.e. if the drive motor is moved at a low speed, then the valve element or the valve device is moved via the friction contact between the coupling surface and the counter coupling surface which is situated between the rotor and the valve device or the valve element, so that the switching position can be changed. The drive motor can subsequently be increased in its speed to such an extent that the friction contact is lifted as has been described and the valve device remains in the reached switching position.

If a purely hydraulic coupling between the drive motor and the valve device is used, then the disengagement can be achieved by way of hydraulic slip, wherein the valve device is then preferably fixed in the second switching position by a second coupling in the manner described above. Given a suitable acceleration of the drive motor, with such a configuration it is also possible to hold the valve element in its initial position without it being moved by the hydraulic coupling. This can be achieved by way of the drive motor being accelerated so rapidly that a pressure build-up which moves the second coupling into the coupled coupling position is effected so rapidly that the second coupling engages before a displacement of the valve element and thus a change of the switching position of the valve device occurs.

The invention is hereinafter described by way of example and by way of the attached figures. The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and specific objects attained by its uses, reference is made to the accompanying drawings and descriptive matter in which preferred embodiments of the invention are illustrated.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings:

FIG. 1 is an exploded view of a centrifugal pump assembly according to a first embodiment of the invention;

FIG. 2 is a perspective view of the lower side of the valve element of the centrifugal pump assembly according to FIG. 1;

FIG. 3 is a perspective view of the pump casing of the centrifugal pump assembly according to FIG. 1 in the opened condition;

FIG. 4 is a sectional view of the centrifugal pump assembly according to FIG. 1;

FIG. 5 is a sectional view of the pump casing of the centrifugal pump assembly according to FIG. 4 with the valve element in a first switching position;

FIG. 6 is a sectional view according to FIG. 5 with the valve element in a second switching position;

FIG. 7 is a schematic view of the hydraulic construction with a heating facility with a centrifugal pump assembly according to FIGS. 1 to 6;

FIG. 8 is an exploded view of a centrifugal pump assembly according to a second embodiment of the invention;

FIG. 9 is a sectional view of the centrifugal pump assembly according to FIG. 8 with the valve element in a first position;

FIG. 10 is a sectional view according to FIG. 9 with the valve element in a second position;

FIG. 11 is an exploded view of the centrifugal pump assembly according to a third embodiment of the invention;

FIG. 12 is a sectional view of the centrifugal pump assembly according to FIG. 11 with the valve element in a first position;

FIG. 13 is a sectional view according to FIG. 12 with the valve element in a second position;

FIG. 14 is an exploded view of a pump assembly with a valve element according to a fourth embodiment of the invention;

FIG. 15 is a sectional view of a centrifugal pump assembly according to the fourth embodiment of the invention;

FIG. 16 is an exploded view of a centrifugal pump assembly according to a fifth embodiment of the invention;

FIG. 17 is a sectional view of the centrifugal pump assembly according to FIG. 16 with the valve element in a first position;

FIG. 18 is a sectional view according to FIG. 17 with the valve element in a second position;

FIG. 19 is an exploded view of a centrifugal pump assembly according to a sixth embodiment of the invention;

FIG. 20 is a sectional view of the centrifugal pump assembly according to FIG. 19;

FIG. 21 is a plan view of the opened pump casing of the centrifugal pump assembly according to FIGS. 19 and 20 with the valve element in a first switching position;

FIG. 22 is a plan view according to FIG. 21 with the valve element in a second switching position;

FIG. 23 is an exploded view of a pump casing with a valve element according to a seventh embodiment of the invention;

FIG. 24 is an exploded view of the pump casing with the valve element according to the seventh embodiment seen from a different side;

FIG. 25 is an exploded view of a centrifugal pump assembly according to an eighth embodiment of the invention;

FIG. 26 is a sectional view of the centrifugal pump assembly according to FIG. 25;

FIG. 27 is a plan view of the opened pump casing of the centrifugal pump assembly according to FIGS. 25 and 26 with the valve element in a first switching position;

FIG. 28 is a plan view according to FIG. 27 with the valve element in a second switching position;

FIG. 29 is an exploded view of the centrifugal pump assembly according to a ninth embodiment of the invention;

FIG. 30 is a perspective view of the centrifugal pump assembly according to FIG. 29 with a removed pump casing and valve element;

FIG. 31 is a perspective view of the motor shaft of the centrifugal pump assembly according to FIGS. 29 and 30 as well as of the coupling part of the valve element;

FIG. 32 is a sectional view of the centrifugal pump assembly according to FIG. 29 with the valve element in a first position;

FIG. 33 is a sectional view according to FIG. 32 with the valve element in a second position;

FIG. 34 is a plan view upon the opened pump casing of the centrifugal pump assembly according to FIGS. 29 to 33 with the valve element in a first switching position;

FIG. 35 is a view according to FIG. 34 with the valve element in a second switching position;

FIG. 36 is a view according to FIGS. 34 and 35 with the valve element in a third switching position;

FIG. 37 is a schematic view of the hydraulic construction of a heating facility with a centrifugal pump assembly according to FIGS. 29 to 36;

FIG. 38 is an exploded view of a centrifugal pump assembly according to a tenth embodiment of the invention;

FIG. 39 is a perspective view of the opened valve element of the centrifugal pump assembly according to FIG. 38;

FIG. 40 is a perspective view of the closed valve element according to FIG. 39;

FIG. 41 is a sectional view of the centrifugal pump assembly according to FIG. 38 with the valve element in a first position;

FIG. 42 is a sectional view according to FIG. 41 with the valve element in a second position;

FIG. 43 is a plan view upon the opened pump casing of the centrifugal pump assembly according to FIGS. 38 to 42 with the valve element in a first switching position;

FIG. 44 is a view according to FIG. 43 with the valve element in a second switching position;

FIG. 45 is a view according to FIGS. 43 and 44 with the valve element in a third switching position;

FIG. 46 is a view according to FIGS. 43 to 45 with the valve element in a fourth switching position; and

FIG. 47 is a schematic view of the hydraulic construction of a heating facility with a centrifugal pump assembly according to FIGS. 38 to 46.

DESCRIPTION OF PREFERRED EMBODIMENTS

Referring to the drawings, the embodiment examples of the pump assembly according to the invention, in the form of a centrifugal pump assembly, which are described in the following description, relate to applications in heating systems and/or air conditioning systems, in which a fluid heat transfer medium, in particular water, is circulated by the centrifugal pump assembly.

The centrifugal pump assembly according to the first embodiment of the invention comprises a motor casing 2, in which an electrical drive motor is arranged. This in the known manner comprises a stator 4 as well as a rotor 6 which is arranged on a rotor shaft 8. The rotor 6 rotates in a rotor space which is separated from the stator space, in which the stator 4 is arranged, by way of a can or a canned pot 10. This means that here it is the case of a wet-running electrical drive motor. The motor casing 2 is connected to a pump casing 12 at an axial end, in which pump casing an impeller 14 which is connected to the rotor shaft 8 in a rotationally fixed manner rotates.

An electronics casing 16 which contains control electronics or a control device for the activation of the electrical drive motor in the pump casing 2 is arranged at the axial end of the motor casing 2 which is opposite to the pump casing 12. The electronics casing 16 could also be arranged at another side of the pump casing 2 in a corresponding manner.

A valve device with a movable valve element 18 is moreover arranged in the pump casing 12. This valve element 18 is rotatably mounted on a pivot 20 in the inside of the pump casing 12, and specifically such that the rotation axis of the valve element 18 is aligned with the rotation axis X of the impeller 14. The pivot 20 is fixed to the base of the pump casing 12 in a rotationally fixed manner. The valve element 18 is not only rotatable about the pivot 20 but is movable in the longitudinal direction X by a certain amount. This linear movability is limited in one direction by way of the pump casing 12, upon which the valve element 18 hits or butts with its outer periphery. In the opposite direction, the movablility is limited by the nut 22, with which the valve element 18 is fastened on the pivot 20. It is to be understood that a different axial fastening of the valve element 18 to the pivot 20 could also be selected instead of the nut 22.

In the pump casing 12, the valve element 18 separates a suction chamber 24 from a delivery chamber 26. The impeller 14 rotates in the delivery chamber 26. The delivery chamber 26 is connected to the delivery connection or delivery branch 28 (delivery nozzle) of the centrifugal pump assembly which forms the outlet of the centrifugal pump assembly. Two suction-side inlets 28 and 30, of which the inlet 28 is connected to a first suction branch 32 and the inlet 30 is connected to the second suction branch 34 of the pump casing 12 run out into the suction chamber 24.

The valve element 18 is configured in a disc-like manner and simultaneously assumes the function of a common deflector plate which separates the suction chamber 24 from the delivery chamber 26. The valve element 18 comprises a central suction opening 26 which comprises a projecting peripheral collar which is engaged with the suction port 38 of the impeller 14 and is essentially in sealing bearing contact with the suction port 38. Facing the impeller 14, the valve element 18 is configured in an essentially smooth manner. The valve element at the side which is away from the impeller 14 comprises two annular sealing surfaces 40 which in this embodiment example are situated on closed, tubular stubs (connection pieces or nozzles). The two annular sealing surfaces 40 are arranged on the sealing element 18 at two diametrically opposite positions with respect to the rotation axis X of this element, so that they can come to sealing bear on the base of the pump casing 12 in the peripheral region of the inlets 28 and 30, so as to close the inlets 28 and 30. Support elements 42 are arranged offset to the sealing surfaces 40 at an angular position of 90° and can likewise come to bear on the peripheral region of the inlets 28, 30, but are distanced to one another such that they do not then close the inlets 28, 30. The inlets 28 and 30 do not lie on the diameter line with respect to the rotation axis X, but on a radially offset straight line, so that on rotation of the valve element 18 about the rotation axis X into a first switching position, the inlet 38 is closed by a sealing surface 40 whilst the support elements 42 lie on the inlet 30 and open this. In a second switching position, the inlet 30 is closed by a sealing surface 40 whilst the support elements 42 bear in the peripheral region of the inlet 28 and open this. The first switching position, in which the inlet 38 is closed and the inlet 30 is opened is represented in FIG. 5. The second switching position, in which the inlet 30 is closed and the inlet 28 is opened is represented in FIG. 6. This means that one can switch between the two switching positions by way of a rotation of the valve element about the rotation axis X by 90°. The two switching positions are limited by a stop element 44 which alternately hits two stops 46 in the pump casing 12.

In an idle position, which is to say when the centrifugal pump assembly is not in operation, a spring 48 presses the valve element 18 into released position, in which the outer periphery of the valve element 18 does not sealingly bear on the pump casing 12 and the sealing surfaces 40 do not sealingly bear in the peripheral region of the inlets 28 and 30, so that the valve element 18 can rotate about the axis 20. If the drive motor is now brought into rotation by the control device 17 in the electronics casing 16, so that the impeller 14 rotates, then a peripheral flow which via the friction co-rotates the valve element 18 in its rotation direction is produced in the delivery chamber 26. I.e. a first hydraulic coupling between the drive motor and the valve element is formed via the rotating flow. The control device 17 is configured such that it can drive the drive motor selectively in two rotation directions. The valve element 18 can therefore likewise be moved in two rotation directions about the rotation axis X depending in the rotation direction of the impeller 14, via the flow which is brought into rotation by the impeller 14, since the flow in the peripheral region of the impeller 14 always runs in its rotation direction. The valve element 18 can therefore be rotated between the two switching positions which are limited by the stops 46.

If the impeller 14 rotates at a sufficient speed, then a pressure builds up in the delivery chamber 26 and this pressure produces a pressing force on the surface of the valve element 18 which surrounds the suction opening 36, said pressing force being opposite to the spring force of the spring 48, so that the valve element 18 is moved in the axial direction X against the spring force of the spring 48 such that it comes to sealingly bear at its outer periphery on an annular contact shoulder 50 on the pump casing 12. Depending on the switching position, one of the sealing surfaces 40 simultaneously comes to sealingly bear on the periphery of one of the inlets 28 and 30, so that one of the inlets 28, 30 is closed. The support elements 42 come to bear on the other inlet, so that this inlet remains open and a flow path from this inlet 28, 30 to the suction opening 36 and from there into the inside of the impeller 14 is given. A frictional contact between the valve element 18 and the pump casing 12 is simultaneously created by way of the bearing of the valve element 18 on the contact shoulder 50 and on the sealing surface 40 in the peripheral region of one of the inlets 28, 30. This frictional contact forms a second coupling which fixes the valve element. This frictional contact ensures that the valve element 18 is held in the reached switching position. This permits the drive motor to be briefly taken out of operation and to be brought into operation again in the opposite rotation direction without the valve element 18 being rotated. If the switching-off and restarting operation of the motor are effected rapidly enough, then the pressure in the delivery chamber 26 does not reduce to the extent that the valve element 18 can again move in the axial direction into its released position. This permits the impeller to always be driven in its preferred rotation direction, for which the blades are configured, on operation of the centrifugal pump assembly and to only use the opposite rotation direction for moving the valve element 18 in the opposite rotation direction. The impeller 14 can rotate further when the valve element 18 is in its bearing position, which is to say contacting position, in which a frictional bearing contact is given and the thus formed second coupling is engaged. The flow continues to run in the delivery chamber 26 without co-rotating the valve element 18. This means that the hydraulic first coupling which is formed between the impeller 14 and the valve element 18 disengages due to slip.

The described centrifugal pump assembly according to the first embodiment of the invention can be applied for example in a heating system as is shown in FIG. 7. Such a heating system is usually applied in apartments or houses and serves for heating the building or for the provision of heated service water. The heating facility comprises heat source 52, for example in the form of a gas heating boiler. A heating circuit 54 which leads for example through various radiators of a building is also present. A secondary heat exchanger 56, via which service water can be heated is moreover provided. A switch-over valve which selectively leads the heat transfer medium flow through the heating circuit 54 or the secondary heat exchanger 56 is usually required in such heating facilities. Regarding the centrifugal pump assembly 1 according to the invention, this valve function is assumed by the valve element 18 which is integrated into the centrifugal pump assembly 1. The control is effected by the control device 17 in the electronics casing 16. The heat source 52 is connected to the delivery branch 27 of the pump casing 12. A flow path 58 is connected to the suction branch 32, whereas a flow path 60 through the heating circuit 54 is connected to the suction branch 34. One can therefore switch between the flow path 58 through the secondary heat exchanger 56 and the flow path through the heating circuit 54 depending on the switching position of the valve element 18, without a valve with an additional drive becoming necessary.

The second embodiment example according to FIGS. 8 to 10 differs from the first embodiment example in respect to the construction of the valve element 18′. In this embodiment example too, the valve element 18′ separates the delivery chamber 26 from a suction chamber 24 of the pump casing 12. The valve element 18 comprises a central suction opening 36′, into which the suction port 38 of the impeller 14 sealingly engages. Opposite the suction opening 36, the valve element 18′ comprises an opening 62 which can be selectively brought to overlap with one of the inlets 28, 30 depending on the switching position of the valve element 18′. In this embodiment example, the inlets 28′, 30′ with regard to shaping differ from the inlets 28, 30 according to the preceding embodiment. The valve element 18′ comprises a central projection 64 which engages into a central hole 60 in the base of the pump casing 12 and is rotatingly mounted there about the rotation axis X. The projection 64 in the hole 66 simultaneously permits an axial movement along the rotation axis X, said movement being limited in one direction by the base of the pump casing 12 and in the other direction by the impeller 14. At its outer periphery, the valve element 18′ comprises a pin 68 which engages into a semicircular groove 70 on the base of the pump casing 12. The ends of the groove 70 serve as stop surfaces for the pin 68 in the two possible switching positions of the valve element 18′, wherein in a first switching position the opening 62 lies above the inlet 28′ and in the second switching position the opening 62 lies above the inlet 30′ and the respective other inlet is closed by the base of the valve element 18′. The rotation movement of the valve element 18′ between the two switching positions in this embodiment example is also effected by the flow which is caused in the delivery chamber 26 by the impeller 14 and which forms a first hydraulic coupling. The valve element 18′ is provided with projections 72 which are directed into the delivery chamber 26, in order to be able to transmit this flow onto the valve element 18′ in a better manner. If the centrifugal pump assembly 1 is taken out of operation, the spring 48 presses the valve element 18′ into the released position which is shown in FIG. 10 and in which it does not bear on the base in the periphery of the inlets 28′ and 30′. I.e. the second coupling is released. In this position, the valve element 18′ abuts axially with a central pin 74 upon the face side of the motor shaft 8 and is limited in its axial movement by thus stop. If the pressure in the delivery chamber 26 is adequately large, the valve element 18′ is pressed into the bearing (contacting) position which is shown in FIG. 9 and in which the valve element 18′ comes to bear on the base of the pump casing 12 in the peripheral region of the inlets 28′ and 30′, and the pin 74 is simultaneously lifted from the face side of the rotor shaft 8. I.e. the second coupling is engaged. In this position, the rotor impeller 14 then rotates in normal operation of the centrifugal pump assembly. I.e. the hydraulic first coupling disengages due to slip.

The third embodiment example according to FIGS. 11 to 13 shows a further possible embodiment of the valve element 18″. This embodiment example differs from the preceding embodiment examples with regard to the construction of the valve element 18″. This valve element is configured as a valve drum. The pump casing 12 corresponds essentially to the construction according to FIGS. 1 to 6, wherein in particular the arrangement of the inlets 28 and 30 corresponds to the arrangement which is described by way of the first embodiment example. The valve drum of the valve element 18″ consists of a pot-like lower part which is closed by a cover 78. The cover 78 faces the delivery chamber 26 and comprises the central suction opening 36 which engages with its axially directed collar into the suction port 38 of the impeller 14. At the opposite side, the base of the lower part 36 comprises an inlet opening 80 which is brought to overlap with one of thee inlets 28, 30 depending on the switching position, whilst the respective other inlet 28, 30 is closed by the base of the lower part 26. The valve element 18″ is rotatably mounted on a pivot 20 which is fastened in the base of the pump casing 12, wherein the rotation axis which is defined by the pivot 20 corresponds to the rotation axis X of the impeller 14. In this embodiment example too, the valve element 18″ is axially displaceable along the pivot 20 by a certain amount, wherein a spring 48 which in the idle position presses the valve element 18″ into its released position which is shown in FIG. 13 is present here too. Here too, a releasable second coupling is therefore created for holding the valve element 18″. In this embodiment example too, the released axial position is limited by the nut 22. In the released position, the valve element 18″ is rotatable by way of the flow which is created by the impeller 14, as described previously, which is to say a hydraulic coupling (first coupling) between the impeller 14 and the valve element 18″ is created, as has been described beforehand. In the bearing position which is shown in FIG. 12, on the one hand one of the inlets 28, 30 is sealingly closed depending on the switched position. On the other hand, a sealing between the suction chamber 24 and the delivery chamber 26 is effected due to the valve element 18″ bearing on the contact shoulder 50.

In this embodiment example, the mounting of the valve element 18″ on the pivot 20 is moreover encapsulated by two sleeves 82 and 84, so that these regions are protected from contamination by the delivered fluid and can be possibly pre-lubricated. A very easy-motion mounting is sought after, in order to ensure the easy rotatability of the valve element 18″ by the flow which is caused by the impeller 14. It is to be understood that the mounting can be encapsulated accordingly also in the case of the other embodiment examples which are described here.

FIGS. 14 and 15 show a fourth embodiment example, concerning which the construction of the pump casing 12 corresponds to the construction of the pump casing 12 according to the first and the third embodiment example. In this embodiment example, the rotation movement of the valve element 18 c is assisted by the suction-side flow, which is to say the flow which enters into the suction port 38 of the impeller 14. Since the suction-side flow is also produced by the centrifugal pump assembly in a circulation system, in which a centrifugal pump assembly as is described here is applied, an indirect coupling of the impeller 14 to the valve element 18 c is also created via the suction-side flow, said indirect coupling representing a first hydraulic coupling. In this embodiment too, the valve element 18 c is configured in an essentially drum-like manner and comprises a cover 28 which faces the delivery chamber 26 and which is with a central suction opening 36 which is engaged with the suction port 38 as has been described beforehand. The lower part 76 b which is shown here comprises two entry openings 80 which can be brought to overlap with one of the inlets 28, 30 depending on the switching position, wherein the respective other inlet 28, 30 is sealingly closed by the base of the lower part 46 b, as has been described with the preceding embodiment example. Guide vanes 86 with blades, into which the flow enters radially from the inlet openings 80 and exits axially to the central suction opening 36 are arranged between the lower part 76 b and the cover 78. A torque about the pivot 20 is also produced by the blades of the guide vanes 86, by way of which torque the valve element 18 c can be moved between the switching positions. This functions essentially as has been described previously. A spring 48, as has been described previously, can additionally be provided, in order to move the valve element 18 c into a released position. With this embodiment example, the restoring movement is effected by a weight 88, since a torque is always produced in the same direction independently of the direction, in which the impeller 14 rotates, on account of the shaping of the blades of the guide vanes 86. On operation, the centrifugal pump assembly is always situated in the installation position which is shown in FIG. 15 and in which the rotation axis X extends horizontally. When the centrifugal pump assembly is switched off, the valve element 18 c always rotates about the pivot 20 such that the weight 88 lies at the bottom. The valve element 18 c can be rotated against this restoring force which is produced by the weight 88, by way of the torque produced by the guide vanes 86, wherein a pressure can be built up in the delivery chamber 26 in such a rapid manner by way of a very rapid starting operation of the drive motor, that the valve element 18 c gets into its bearing position, as has been described above, in which position it is non-positively held on the pump casing 12 in a rotationally fixed manner without having to be moved out of its idle condition. I.e., a second coupling as is described above is also realized here. It is to be understood that a restoring of the valve element by way of gravity or by way of another restoring force independently of the drive could also be applied to the other embodiment examples which are described here. If the valve element 18 c is in the bearing position, then the first coupling which is formed by the guide vanes 86 disengages due to slip, which is to say that the flow continues to run through the guide vanes without however being able to cause a rotation of the valve elements.

The fifth embodiment example according to FIGS. 16 to 18 differs from the preceding embodiment examples again in the construction of the valve element. With regard to this embodiment example, the valve element 18 d is configured conically. The valve element 18 d comprises a conical, pot-like lower part 76 d which is closed by a cover 78 d, wherein a central suction opening 36 which is engaged with the suction port 38 of the impeller 14 in the previously described manner is again formed in the cover 78 d. Inlet openings 90 which by way of rotating the valve element 18 d can be selectively brought to overlap with inlets which are connected to the suction branches 32 and 34, in order to create a flow path through the inside of the valve element 18 d to the suction opening 36 are formed in the conical peripheral surface of the lower part 76 b. Sealing surfaces 92 which can close the respective other inlet are formed on the conical lower part between the inlet openings 90. As also with the second embodiment example according to FIGS. 8 and 10, here the valve element 18 d also comprises a pin-like projection 64 which engages in a recess on the base of the pump casing 12 and there rotatably mounts the valve element 18 d about the rotation axis X. Here too, an axial movement is possible between a released position, as is shown in FIG. 18 and a bearing (contacting) position as is shown in FIG. 17, in order to form a releasable second coupling. In the released position, the lower part 76 d of the valve element 18 d essentially does not bear on the pump casing 12 so that it can be rotated by the flow in the delivery chamber 26 as a first hydraulic coupling, as has been described with regard to the previously described embodiment examples. Here, a to-and-fro movement of the valve element 18 d can again be achieved in a manner dependent on the rotation direction of the impeller, wherein here too, the rotation movement of the valve element 18 d can also be limited by stops which are not shown. In the bearing position according to FIG. 17, on the one hand a sealing bearing contact of the valve element 18 d is effected, and on the other hand it is non-positively held, so that again, as long as the pressure in the delivery chamber 26 is sufficiently large, it is not moved between the switching positions even given a direction change of the impeller 14.

The sixth embodiment example according to FIGS. 19 to 22 is similar to the second embodiment example according to FIGS. 8 to 10. The pump casing 12 corresponds essentially to the construction which is represented there and has been described. The motor casing 2 with the electronics casing 16 and the can 10 also correspond to the construction according to the second embodiment example. The valve element 18 e has a construction which is very similar to the construction of the valve element 18′. What is merely absent are the projections 76 and pin 74. In contrast, the opening 62 is formed in exactly the same manner. The suction opening 36 e also corresponds essentially to the construction of the suction opening 36′. The valve element 18 e is rotatingly mounted on a hollow pivot which is inserted into the hole 66 in the base of the pump casing 12. In this embodiment example, the spring 48 is arranged in the inside of the hollow axis 94.

Depending on the switching position of the valve element 18 e, the opening 62 either comes to lie over the inlet 28′ or the outlet 30′, in order to either open a flow path from the suction branch 32 to the impeller 14 or from the suction branch 34 to the impeller 14. In this embodiment too, the valve element 18 e is additionally axially movable along the rotation axis X which is the rotation axis of the impeller 14 and of the valve element 18 e, in order to from a second coupling. In an idle position, in which the centrifugal pump assembly is not in operation, the valve element 18 e is pushed by the spring 48 into a released position, in which the surface of the valve element 18 e which is away from the impeller 14 is distanced to the base of the pump casing 12, so that the valve element 18 e can be rotated to and fro about the axis 94 in an essentially free manner between the stops which are formed by the pin 68 and the groove 70. FIG. 21 shows the first switching position, in which the opening 62 lies opposite the inlet 28′ and FIG. 22 shows the second switching position, in which the opening 62 lies opposite the second inlet 30′.

With this embodiment example, the rotation of the valve element 18 e is again effected via the impeller 14, but here a mechanical coupling is provided as a first coupling, said coupling being realized by way of the impeller 14 with its region which surrounds the suction port 38 coming to frictionally bear on the periphery of the suction opening 36 e. The valve element 18 e is therefore co-rotated with the impeller 14 until the pin 68 reaches a stop. The coupling then disengages due to slip. Then, with an increasing pressure in the delivery chamber 26, the valve element 18 e is moved axially into its bearing (contacting) position as described above, in which position the second coupling is therefore engaged and wherein the first coupling disengages from the impeller 14, so that the impeller 14 can then rotate in an essentially frictionless manner.

The seventh embodiment example according to FIGS. 23 and 24 differs from the previously described sixth embodiment in that a tongue 96 which extends into the delivery chamber 26 and which serves as an additional valve element in the delivery chamber 26 is arranged on the valve element 18 f. The pump casing 12 comprises an additional delivery branch 98 which runs out into the delivery chamber 26 separately to the delivery branch 27. Depending on the switching position of the valve element 18 f, the tongue 96 can release the delivery branch 27 or the delivery branch 28 and cover the respective other delivery branch. With this embodiment example therefore, a delivery-side switch-over is envisaged at the delivery side of the impeller 14. A mixing function can be simultaneously realized via the inlets 28′ and 30′, by way of the opening 92 being positioned such that it covers both these inlets 28′, 30′ in a first switching position, so that fluid can flow out of the both inlets 28′, 30′ through the opening 62 and further through the suction port 38. In contrast, in the second switching position the opening 62 covers only the inlet 28′, whereas the inlet 30′ is closed by the base of the valve element 18 f in the manner described above. The delivery branch 27 is simultaneously closed and the delivery branch 98 released. The movement of the valve element 18 f can be realized in the manner described above via the impeller 14 and a mechanical coupling which disengages by way of the axial displacement of the valve element 18 f given a sufficiently high pressure in the delivery chamber 26. The valve element 18 f is mounted on the rotor shaft 8 in this embodiment example.

The eighth embodiment according to FIGS. 25 to 28 differs from the sixth embodiment with regard to the configuration of the first mechanical coupling between the rotor shaft 8 and the valve element 18 g. Concerning this embodiment example, the valve element 18 g is mounted directly on the rotor shaft 8 which is configured in an extended manner and extends up to into the hole 66 in the base of the pump casing 12. Two ring segments 100 with plain bearing characteristics, in particular of ceramic are arranged in the inside of the valve element 18 g. The ring segments 100 are held together by a clamping ring 102 and are pressed against the rotor shaft 8. In this example, the two ring segments 100 form an essentially ⅔ ring. The valve element 18 g with a projection 104 on its inner periphery engages in the region of the ring segment which is absent for a complete ring, so that the two ring segments 100 are arranged in the inside of the valve element 18 g in a rotationally fixed manner A passage 106 which effects the valve function remains in the region of the absent ring segment, which is to say adjacent to the projection 104.

In a first switching position which is shown in FIG. 27, the passage 106 can lie opposite inlet 30′ and in a second switch position which is shown in FIG. 28 can lie opposite the inlet 28′. The other inlet is closed in each case. For this, the valve element 18 g can be pressed in the axial direction into bearing contact on the base of the pump casing 2 which surrounds the inlets 28′ and 30′, by way of the pressure prevailing in the delivery chamber 26, in accordance with the embodiments described above.

The movement of the valve element 18 g is effected via a first coupling by way of the drive of the impeller 14. At the start, the rotor shaft 8 bears non-positively on the inner periphery of the ring segments 10 and co-rotates these and thus the valve element 18 g. Stops for both switching positions can be formed in the pump casing 12 in the manner described above.

When the valve element 18 g reaches one of these stops, then the pump shaft 8 slides through in the inside of the ring segments 100, i.e. the coupling disengages. Moreover, a lubrication film forms between the outer periphery of the rotor shaft 8 and the inner surfaces of the ring segments 100 in the manner of a plain bearing, given an increasing speed of the rotor shaft 8, so that the rotor shaft 8 can then rotate in an essentially frictionless manner in the inside of the ring segments 100. This means that for adjusting or actuating the valve element 18 g between its two switching positions, the drive motor is moved by the control device 17 preferably at a lower speed than the speed at which the impeller 14 is rotated on operation. The drive motor can be driven in two rotation directions in the manner described above, for moving the valve element 18 g to and fro, wherein again after reaching the desired switching position, by way of a rapid speed increase, one can succeed in the valve element 18 g remaining in the previously reached switching position on account of the pressure in the delivery chamber 26 and the bearing contact of the valve element on the base of the pump casing 12, in the manner described above.

With regard to the ninth and tenth embodiment according to FIGS. 29 to 37 as well as 38 to 47, a mechanical coupling is likewise provided between the drive motor and the valve element, wherein concerning these embodiments, the drive motor can be activated in two different operational types or modes by way of the control device 17. In a first operation mode which corresponds to the normal operation of the circulation pump assembly, the drive motor rotates in the conventional manner at a desired speed which can be adjusted, in particular by the control device 17. In the second operating mode, the drive motor is activated (controlled) in open loop operation, so that the rotor can be rotated stepwise in individual angular steps which are smaller than 360°. The drive motor can therefore be moved in individual steps in the manner of a stepper motor, which concerning these embodiment examples is used in order to move the valve element in small angular steps into a defined position in a targeted manner, as is described hereinafter.

With regard to the ninth embodiment according to FIGS. 29 to 37, a mixing valve as can be used for example for temperature adjustment for a floor heating is integrated in the pump casing 2.

The motor casing 2 with the electronics casing 16 corresponds to the previously described embodiment. The pump casing 12 is constructed in essentially the same manner as the pump casing according to the first embodiment according to FIGS. 1 to 6, and it is only the outer configuration which is different. With this ninth embodiment, the valve element 18 h is likewise configured in a drum-like manner and consists of a pot-like lower part 76 h which at its side which faces the impeller 14 is closed by a cover 78 h. A suction opening 36 is formed in the central region of the cover 78 h. The valve element 18 h is rotatably mounted on a pivot 20 which is arranged in the base of the pump casing 12. Here, the rotation axis of the valve element 18 h corresponds to the rotation axis X of the rotor shaft 8 h, as is the case with the examples described above. Here, for forming a second releasable coupling, the valve element 18 h is likewise axially displaceable along the axis X and is pressed by a spring 48 into the idle position which is shown in FIG. 33 and in which the valve element 18 h is located in released position, in which the lower part 76 h does not bear on the base of the pump casing 12, so that the valve element 18 h is essentially freely rotatable about the pivot 20. In the released position, the face end of the rotor shaft 8 h which is configured as a first coupling 108 serves as an axial stop. The coupling 108 engages with a counter coupling 110 which is arranged on the valve element 18 h in a rotationally fixed manner. The coupling 108 comprises beveled (inclined) coupling surfaces which along a peripheral line essentially describe a saw-toothed profile in a manner such that a torque transmission from the coupling 108 onto the counter coupling 110 is only possible in one rotation direction, specifically in the rotation direction A in FIG. 31. In contrast, the coupling slips through in the opposite rotation direction B, wherein an axial movement of the valve element 18 h occurs. The rotation direction B is that rotation direction, in which the pump assembly is driven in normal operation. In contrast, the rotation direction A is used for the targeted actuation of the valve element 18 h. This means that a rotation-direction-dependent first coupling is formed here. However, concerning this embodiment too, the counter coupling 110 also disengages from the coupling 108 due to the pressure in the delivery chamber 26. If the pressure in the delivery chamber 26 increases, then a pressing force which is opposed to the spring force of the spring 48 and which exceeds this acts upon the cover 78 h, so that the valve element 18 h is pressed into the bearing position as is shown in FIG. 32. In this position, the lower part 76 h bears on the base side of the pump casing 12, so that on the one hand the valve element 18 h is non-positively held and on the other hand a sealed bearing contact is achieved, said contact sealing the delivery side and the suction side with respect to one another in the subsequently described manner.

The pump casing 12 comprises two suction branches 32 and 34, of which the suction branch 32 runs out at an inlet 28 h and the suction branch 34 at an inlet 30 h, in the base of the pump casing 12 into the interior of this, which is to say into the suction chamber 24. The lower part 76 h of the valve element 18 h in its base comprises an arched opening 112 which extends essentially over 90°. FIG. 34 shows a first switching position, in which the opening 112 only overlaps the inlet 30 h, so that a flow path only from the suction branch 34 to the suction opening 36 and therefore to the suction port 38 of the impeller 14 is given. The second inlet 28 h is sealingly closed by the base of the valve element 18 h which bears in the peripheral region of this second inlet. FIG. 36 shows the second switching position, in which the opening 112 only overlaps the inlet 28 h, with the inlet 30 h closed. In this switching position, only a flow path from the suction branch 32 to the suction port 38 is opened. FIG. 35 now shows an intermediate position, in which the opening 112 overlaps both inlets 28 h and 30 h, wherein the inlet 30 h is only partly released. A mixing ratio between the flows from the inlets 28 h and 30 h can be changed by way of changing the degree of release of the branch 30 h. The valve element 18 h can also be adjusted or actuated in small steps via the stepwise actuation of the rotor shaft 8 h, in order to change the mixing ratio.

Such a functionality can be applied for example in a hydraulic system as is shown in FIG. 37. There, the centrifugal pump assembly with the integrated valve as has been described above is characterized by the dashed line 1. The hydraulic circuit comprises a heat source 114 in the form of a gas heating boiler for example, the outlet of which running out for example into the suction branch 34 of the pump casing 12. In this example, a floor heating circuit 116 whose return is connected to the inlet of the heat source 114 as well as to the suction branch 32 of the centrifugal pump assembly 114 connects onto the delivery branch 37 of the centrifugal pump assembly 1. A further heating circuit 120 can be supplied with a heat transfer medium which has the outlet-side temperature of the heat source 114, via a second centrifugal pump assembly 118. The floor heating circuit 116 in contrast can be regulated in its feed temperature in a manner such that cold water from the return is admixed to the hot water at the outlet side of the heat source 114, wherein the mixing ratio can be changed by way of changing the opening ratios of the inlets 28 h and 30 h in the manner described above by way of rotating the valve element 18 h.

The tenth embodiment example according to FIGS. 38 to 47 shows a centrifugal pump assembly which additionally to the previously described mixing function yet comprises a switch-over functionality for the additional supply of a secondary heat exchanger for the heating of service water.

Concerning this embodiment, the mounting and drive of the valve element 18 i is effected just as with the ninth embodiment. In contrast to the valve element 18 h, the valve element 18 i additionally to the opening 112 comprises a through-channel 122 which extends from an opening 124 in the cover 78 i to an opening in the base of the lower part 76 i and therefore connects the two axial ends of the valve element 18 i to one another. An arched bridging opening 126 is moreover yet formed in the valve element 18 i and this opening is closed to the delivery chamber 28 by the cover 78 i and is only open to the lower side, which is to say to the base of the lower part 76 i and thus to the suction chamber 24

The pump casing 12 comprises a further branch 128, apart from the delivery branch 27 and both previously described suction branches 34 and 32. The branch 128 runs out into an inlet 130 in the base of the centrifugal pump assembly 12 additionally to the inlets 28 h and 30 h into the suction chamber 24. The various switching positions are explained by way of FIGS. 43 to 46, wherein the cover 78 i of the valve element 18 i is shown in a partly opened manner in these figures, in order to clarify the position of the openings which lie therebelow. FIG. 43 shows a first switching position, in which the opening 112 lies opposite the inlet 30 h, so that a flow connection from the suction branch 34 to the suction port 38 of the impeller 14 is created. In the switching position according to FIG. 44, the opening 112 lies over the inlet 130, so that a flow connection from the branch 128 to the suction opening 36 and via this into the suction port 38 of the impeller 14 is created. In a further switching position which is shown in FIG. 45, the opening 112 lies over the inlet 30 h, so that again a flow connection from the suction branch 34 to the suction port 38 of the impeller 14 is given. A partial overlapping of the opening 124 and of the through-hole 122 with the inlet 28 h simultaneously takes place, so that a connection between the delivery chamber 26 and the suction branch 32 which functions here as a delivery branch is created. The bridging opening 126 simultaneously overlaps the inlet 130 and a part of the inlet 28 h, so that a connection from the branch 128 to the branch 32 is likewise created via the inlet 130, the bridging opening 126 and the inlet 28 h.

FIG. 46 shows a fourth switching position, in which the through-channel 122 completely overlaps the inlet 28 h, so that the branch 32 is connected to the delivery chamber 26 via the through-channel 122 and the opening 124. Simultaneously, the bridging opening 126 continues to cover only the inlet 130. The opening 112 continues to cover the inlet 30 h.

Such a centrifugal pump assembly can be applied for example in a heating system as is shown in FIG. 47. Here, the dashed line delimits the centrifugal pump assembly 1, as has just been described by way of FIGS. 38 to 46. The heating system again comprises a primary heat exchanger or a heat source 114 which for example can be gas heating boiler. At the outlet side, the flow path runs into a first heating circuit 120 which can be formed for example by way of conventional radiators. A flow path simultaneously branches to a secondary heat exchanger 56 for heating service water. The heating system moreover comprises a floor heating circuit 116. The returns of the heating circuit 120 and of the floor heating circuit 116 run out into the suction branch 34 on the pump casing 12. The return from the secondary heat exchanger 56 runs out into the branch 128 which provides two functionalities as is described hereinafter. The branch 32 of the pump casing 12 is connected to the feed of the floor heating circuit 116.

When the valve element 18 i is located in the first switching position represented in FIG. 43, the impeller 14 delivers fluid from the suction branch 34 via the delivery branch 27 through the heat source 140 and the heating circuit 120 and back to the suction branch 34. If the valve element 18 i is located in the second switching position which is shown in FIG. 44, the facility is switched over to service water operation and in this condition the pump assembly or the impeller 14 delivers fluid from the branch 128 which serves as a suction branch, through the delivery branch 27, via the heat source 114 through the secondary heat exchanger 56 and back to the branch 128. The floor heating circuit 116 is additionally supplied if the valve element 18 i is located in the third switching position which is shown in FIG. 45. The water flows into the suction port 38 of the impeller 14 via the suction branch 34 and is delivered via the delivery branch 27 through the first heating circuit 120 via the heat source 114 in the described manner. The fluid at the outlet side of the impeller 14 simultaneously exits the delivery chamber 26 into the opening 124 and through the through-channel 122 and thus flows to the branch 32 and via this into the floor heating circuit 116.

Fluid simultaneously flows via the bridging opening 126 into the branch 32 via the branch 128 and the inlet 130, in the switching position which is shown in FIG. 45. This means that here water flows via the heat source 114 through the secondary heat exchanger 26 and the branch 128 to the branch 32. Since essentially no heat is taken at the secondary heat exchanger 56 in this heating operation, hot water is admixed to the branch 32 additionally to the cold water which flows out of the delivery chamber 26 to the branch 32 via the through-channel 130. The quantity of the admixed warm water at the branch 32 can be varied by way of changing the degree of opening via the valve position 18 i. FIG. 46 shows a switching position, in which the admixing is switched off and the branch 32 is exclusively in direct connection with the delivery chamber 26. In this condition, the water in the floor heating circuit 116 is delivered in the circuit without any supply of heat. It is to be recognized that with this embodiment, a switching between the heating and service water heating as well as simultaneously the supply of heating circuits with two different temperatures, specifically of a first heating circuit 120 with the exit temperature of the heat source 114 and of a floor heating circuit 116 with a temperature which is reduced via a mixing function can also be achieved by way of the change of the switching positions of the valve element 18 i.

It is to be understood that the various previously described embodiments can be combined with one another in a different manner. Thus the different described drive modes of the valve element can be essentially arbitrarily combined with different geometric configurations of the valve element as have likewise been described above. The different valve functionalities (for example mixing and switching-over) can likewise be realized and combined with different drive modes. These different combination possibilities which are to be derived from the preceding embodiment examples are expressly encompassed by the invention.

Concerning the described examples, the valve element with the impeller is always arranged in a common pump casing, which therefore forms a combined valve and pump casing. It is to be understood that this pump casing can also be configured of several parts.

While specific embodiments of the invention have been shown and described in detail to illustrate the application of the principles of the invention, it will be understood that the invention may be embodied otherwise without departing from such principles. 

1. A pump assembly comprising: an electric drive motor; at least one impeller which is driven by the drive motor; and at least one valve device which is situated in a flow path through the pump assembly and which is movable at least between a first switching position and a second switching position, wherein the valve device is coupled to the drive motor via a first coupling such that a movement of the drive motor is transmitted onto the valve device and the valve device is movable from the first into the second switching position by way of a rotation movement of the drive motor and the first coupling is releasable by way of increasing the speed of the drive motor and/or increasing pressure at the outlet side of the impeller and/or by way of slip, such that the coupling between the drive motor and the valve device is reduced or lifted.
 2. A pump assembly according to claim 1, wherein a second releasable coupling is provided between at least one movable part of the valve device and a pump casing which surrounds the impeller, said second releasable coupling being movable from a released, first coupling position into a holding, second coupling position by way of the pressure at the outlet side of the impeller.
 3. A pump assembly according to claim 2, wherein the first and the second coupling are configured such that the first coupling in a first coupling released position has a lower holding force than the second coupling in a second coupling holding position and the first coupling in a first coupling coupled position has a greater holding force than the second coupling in a second coupling released position.
 4. A pump assembly according to claim 1, wherein on operation of the pump assembly, the drive motor produces a torque which is larger than the holding force of the first coupling in a first coupling coupled position.
 5. A pump assembly according to claim 1, wherein the valve device is configured as a switch-over valve which permits a switching-over between two flow paths and/or is configured as a mixing device, in which fluid is mixed from two flow paths, wherein the mixing device is configured such that the mixing ratio is different in the two switching positions.
 6. A pump assembly according to claim 1, wherein the valve device has a valve function in a flow path at the suction side of the impeller and/or in a flow path at the delivery side of the impeller.
 7. A pump assembly according to claim 1, wherein the valve device comprises at least one movable valve element as well as stop elements which define the first and the second switching position and of which at least one is position adjustable.
 8. A pump assembly according to claim 1, wherein the valve device comprises at least one movable valve element which interacts with two valve openings such that in the first switching position of the valve device, a first valve opening is covered by the valve element to a greater extent than in the second switching position and in the second switching position a second valve opening is covered to a greater extent than in the first switching position.
 9. A pump assembly according to claim 1, wherein the valve device comprises a movable valve element which comprises at least one sealing surface and a pressure surface, wherein the pressure surface is connected to a delivery chamber which surrounds the impeller, such that the valve element is pressed with the sealing surface against a contact surface by way of the pressure which acts upon the pressure surface, wherein the contact surface forms a valve seat.
 10. A pump assembly according to claim 1, wherein the valve device comprises a rotatable valve element which via the first coupling is releasably coupled to a rotor of the drive motor, wherein the rotation axis of the valve element is aligned with the rotation axis of the drive motor.
 11. A pump assembly according to claim 1, wherein the drive motor driveable in two rotation directions and the valve device is configured such that the first switching position is achieved by the drive of the drive motor in a first rotation direction and the second switching position is reached by the drive of the drive motor in a second rotation direction.
 12. A pump assembly according to claim 2, wherein the first and/or the second coupling is a friction coupling, a magnetic coupling and/or a hydraulic coupling, which has slip.
 13. A pump assembly according to claim 1, wherein the first coupling comprises at least one coupling element which is movable between a coupled and a released position, wherein the movement direction between the coupled and the released position runs transversely to a force direction of the force which is to be transmitted by the coupling onto the valve device.
 14. A pump assembly according to claim 13, wherein a valve element of the valve device forms the movable coupling element.
 15. A pump assembly according to claim 13, wherein the coupling element is subjected to a biasing force via a biasing element, said biasing force forcing the coupling element into the coupled position.
 16. A pump assembly according to claim 15, wherein the coupling element comprises a pressure surface, the connection of said pressure surface to a delivery chamber which surrounds the impeller and the arrangement of said pressure surface being such that a pressure acting upon the pressure surface produces a force which is directed oppositely to the biasing force.
 17. A pump assembly according to claim 13, wherein the coupling element comprises a coupling surface which in the coupled condition is in frictional contact with a counter coupling surface, and that the coupling surface and the counter coupling surface are configured and surrounded by a lubricant, such that a lubricant film which overcomes the frictional contact forms between the coupling surface and the counter coupling surface on increasing the speed of the drive motor. 